Many of these are yoga positions. Work to achieve them slowly. With time it will come. ~ Muscle assisted shoulder stretches: tricep stretch, one arm over the head, both arms over the head, cow face yoga position, grab an elbow be.
Stretching is key! One thing that a lot of people forget to do is stretch and warm up. The best way to workout a muscle is to make sure that it is stretched and ready to go! Here are some great ideas for upper body stretches!